[Technical Filed]
The present invention relates to a wireless power transmission apparatus and a direct drive type system including the apparatus, and in particular to a wireless power transmission apparatus based on a magnetic resonant method and a direct drive type system including the apparatus.
[Related Art]
Direct drive type systems have been in heavy use such as in factories. Such a direct drive type system includes a movable member that can move along a fixed rail member. As an example of the direct drive type system, a direct drive type robot is well known as disclosed such as in JP-A-2009-208941.
The direct drive type robot includes a fixed linear or curved rail member and a movable member that moves along the rail member. The movable member is supported and guided by the rail member. The movable member has a motor and moves along the rail member using the drive force of the motor. In the direct drive type robot, electric power is fed from a power source to the motor,
The electric power is fed to the motor by way of a plurality of power cables housed in a cable carrier. The cable carrier is a flexible casing that houses, supports and guides piping and the power cables. Such a casing is well known as a cableveyor (trademark).
The cable carrier that houses the power cables is necessary between a power source and the movable member. The cable carrier is required to follow the movable member that moves along the rail member. Accordingly, the cable carrier is required to be set up in conformity with the moving range of the movable member. As the moving range of the movable member increases, the entire length of the cable carrier increases. In order to be in concert with the reciprocal movement of the movable member along the rail member, the cable carrier is used in a state where at least a part thereof is turned over in a shape of U.
However, in a direct drive type robot including such a cable carrier, inevitably, the movable member moves being accompanied by the cable carrier. Therefore, the output of the motor that drives the movable member is required to cover not only the weight of the movable member and the weight of the member conveyed by the movable member, but also the weight of the cable carrier. As a result, with the increase of the output of the motor, the size of the motor is increased.
Further, since the cable carrier moves with the movable member, the cable carrier is repeatedly brought into contact with the peripheral members. The contact between the cable carrier and the peripheral members causes noises. Further, the abrasion generates dust. In particular, in manufacturing facilities for precision equipment, such as electronic equipment and semiconductors, dust may cause quality loss of the products.
Direct drive type robots based on conventional art, which include a carrier that causes abrasion, are required to be improved so as to be more favorably applied to such manufacturing facilities.
A main purpose of introducing robots to facilities is to enhance work efficiency in the facilities. In a direct drive type robot, the movable member that moves along the rail member repeatedly moves along the rail member and stops at an optionally selected position for a predetermined work. The stop position and the moving distance of such a movable member are optionally set by users and thus depend on the facilities that introduce the direct drive type robot.
In a direct drive robot based on conventional art that includes a cable carrier as described above, the movable member receives supply of electric power by way of the cable carrier. Accordingly, supply of electric power to the movable member never stops, irrespective of the stop position and the moving distance of the movable member. In other words, if the cable carrier is not used, it is necessary to stably feed electric power to the movable member.
In addition, in the facilities introduced with the direct drive type robots, lots of machines other than the robots are at work. Therefore, in eliminating the cable carriers, it is necessary to consider that the elimination will not affect machines other than the robots.